THE ANSWER IS 4 YOU LITTLE KITTY HAAAAAAAAAAAAA.
(edit) Sorry i got carried away. :p
I will get a friend to help with this
Answer:
A chemical indicator is a substance that undergoes a distinct observable change when conditions in its solution change. This could be a color change, precipitate formation, bubble formation, temperature change, or other measurable quality.
Answer:
The stomata open and close to allow the intake of carbon dioxide and release of oxygen.
hope this helps
ples brainliest